1. Field of the Invention
The present invention relates generally to the design of electronic circuits, and more specifically to a low-output-impedance circuit operating from a low supply voltage.
2. Related Art
An output stage generally refers to a portion of a circuit which provides the output signals of interest on corresponding output terminals. The terminals may connect the output stage with the input stage of a subsequent circuit (or to a load in general). The output stage is characterized by an output impedance, which is in theory defined as the impedance seen looking into the terminals.
It is generally desirable that the output impedance be low since the signal strength (voltage, current) would then be available for the actual load that the electrical circuit may be designed to be connected to. Low output impedance can lead to several benefits such as reduced power consumption, potential simplification of circuit design, etc., as is also well known in the relevant arts.
Output stages generally operate from a power supply. The power supply provides the energy (in the form of voltage/current) to generate the output signals. For example, a supply voltage, often termed as Vdd, is provided in operation of several circuits.
It may be desirable to provide output stages with low output impedance which operate from low power supplies in several environments. For example, there is an increasing demand to implement circuits operating with lower supply voltages (e.g., from 3.0 to 1.8 Voltage), and it may thus be desirable to ensure that the output stage also can operate at corresponding low supply voltage.
Various aspects of the present invention address one or more of the above-noted requirements, as described below in further detail.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.